Reference is made to commonly-assigned U.S. patent application Ser. No. 09/799,378 filed concurrently herewith, entitled xe2x80x9cRecording Rewritable Time Related Information on a Labelxe2x80x9d by Stanley W. Stephenson, the disclosure of which is incorporated herein by reference.
The present invention relates to a display having writable segments and uses cholesteric liquid crystal material.
Audio-visual (A/V) recordings, such as movies, can be stored on a variety of media. Currently, such recordings are stored on video cassette record (VCR) tapes or Digital Video Disk (DVD) optical storage disks. Such media is subject to damage and is typically stored in a storage case. Agencies have been developed to provide rental of such recordings on either type of storage media. A renter pays an agency to posses a given recording for a given time period. Agencies rent storage cassettes for variable amounts of time at different prices. Such agencies also rent computer games at a price for a given time period. Financial penalties are be assessed if the media cassette is not returned by a certain return time. It would be useful to display that return time on the storage cassette to prevent late fees.
Currently, a paper receipt is provides a record of the return time to a customer for a given cassette. Alternatively, an adhesive label with the return time could be applied to the case. U.S. Pat. No. 5,040,296 discloses and adhesive label for a VCR cassette having a permanent set of indicia printed and covered with a surface that permits erasable marking. An alternative method is shown in U.S. Pat. No. 5,727,818 wherein indicia formed by pressure from a pointed tip are erased by lifting the protective sheet.
An electronic label is disclosed in U.S. Pat. No. 6,065,701. An adhesive label can be applied to a VCR cassette. The label contains an antenna and integrated circuit that permits the exchange of data between the circuit on the label. The unit can store and transmit data but does not permit a renter to visually determine a return date.
Fabrication of flexible, electronically written display sheets are disclosed in U.S. Pat. No. 4,435,047. A first sheet has transparent ITO conductive areas and a second sheet has electrically conductive inks printed on display areas. The sheets can be glass, but in practice have been formed of Mylar polyester. A dispersion of liquid crystal material in a binder is coated on the first sheet, and the second sheet is bonded to the liquid crystal material. Electrical potential applied to opposing conductive areas operate on the liquid crystal material to expose display areas. The display uses nematic liquid crystal material which ceases to present an image when de-energized.
U.S. Pat. No. 5,437,811 discloses a light-modulating cell having a polymer dispersed chiral nematic liquid crystal. The chiral nematic liquid crystal has the property of being driven between a planar state reflecting a specific visible wavelength of light and a light scattering focal-conic state. Said structure has the capacity of maintaining one of the given states in the absence of an electric field.
It is an object of the present invention to provide a display suitable for use as a display on an article and that can be changed by providing appropriate electrical fields to the display.
This object is achieved by a rewritable display, comprising:
a) a transparent substrate;
b) a first transparent conductor over such substrate;
c) a layer including cholesteric liquid crystal material;
d) a dielectric layer having openings;
e) a second conductor provided over the dielectric layer and into the openings to be in contact with the cholesteric liquid crystal bearing layer which is effective at the position in such openings to be in at least first and second optical states so that written and viewed, be electrically changed by providing appropriate electrical fields to the material; and
f) means for electrically addressing the cholesteric liquid crystal layer to erase previous information and writing appropriate information.
The present invention provides a structural arrangement with openings in the dielectric layer so that a cholesteric liquid crystal material can be easily addressed to write, rewrite and erase information.
It is a further feature that displays in accordance with the present invention are particularly suitable for use on articles or rental devices which provide a user with time information related to their use of the rental device.
An advantage of the present invention is that the device can be a rental media cassette, such as an optical disk or magnetic tape.